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I had on my laptop windows 7 and ubuntu server 9.10 (the partition with windows 7 was automatically selected at boot time). Today I wanted to install ubuntu 10.4, and for that I deleted the 9.10 partition using windows manager, formatting it to a new blank partition.

Since that, every time I turn on my laptop the grub loader appears and I get an error saying:

unknown filesystem
grub rescue>

I tried inserting my windows 7 install disc to repair the installation, but even after I did this 2 times nothing changed.

What should I do in order to repair my boot records?

Thank you.

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up vote 3 down vote accepted

You need to repair/reinstall the Windows 7 boot loader.

Use the Windows 7 install disk and choose Repair your computer then command prompt.

Try typing the following two commands:

bootrec /fixmbr
bootrec /fixboot

If it still doesn't work, then try using diskpart and setting the small 100Mb Windows 7 system drive as active, then run the above two commands again. If still having problems or do not understand this step, please say and I will try to go in to more details.

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this worked like a charm. thank you very much :) – misterjinx Aug 22 '10 at 15:39
Thanks, I too had this problem and it worked when I tried your answer. Awesome :) – Waqar Ahmad Aug 31 '13 at 5:30
worked like a charm – Amir Jan 31 at 18:12

You have to restore something called your "MBR" or Master Boot Record.

The simplest way to do it?

Note that I found that I had to use the command "bootsect /nt60 c: /mbr" instead of what is given on that site (ie; not 'c:/' or 'c:\', but just 'c:', and a '/mbr' at the end). Assuming that the Windows installation is on C drive that is.

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